During an examination of the heart it is important to supply accurate images to the physician to facilitate the procedure. A well established method for providing images of the lumen of a vessel is angiography, where after the injection of a contrast agent (CA) a series of images is acquired for example with the help of X-rays.
There are several approaches to provide images with high image quality. An example for such an approach is a procedure known as digital subtraction angiography (DSA), where a first mask image is acquired using for example X-rays, and then, e.g. after injection of a contrast agent into the vessels to be observed, a contrast image is acquired. Subtracting the mask image from the contrast image presents the observer the relevant information only, which is the lumen of a vessel, yielding an image that is more worthwhile to the observer.
As the heart of a living being is a moving object, single images provide snap shots of the organ during different phases of a cardiac cycle. Furthermore, observing the propagation of the contrast agent over several cardiac cycles allows to present images of different stages of a blood circulation (CA propagation), like a coronary stage, a perfusion stage and a venous stage.
The useful acquired information may be low-contrasted, for example during the perfusion stage, the images may be noisy, and the regions of interest may be moving fast with the heart cycle. Furthermore, for a physician looking at the images or image sequences acquired during an examination it may be difficult to correlate the information acquired during the different coronary stages of the blood circulation.
There may be a need for an improved method or apparatus for dynamically visualizing high quality images, in particular images comprising coronary information.